function checkIfPangram(sentence: string): boolean {
    // if(sentence.length < 26){
    //     return false
    // }
    // const arr = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z']
    // let result = true
    // arr.forEach(item => {
    //     if(sentence.indexOf(item) === -1) {
    //         result = false
    //     }
    // })
    // return result
    const set = new Set(sentence)
    return set.size === 26
};

const sentence = "leetcode"
console.log(checkIfPangram(sentence))